refactor aws.js

osser · Nov 8, 2013 · 4d637ed · 4d637ed
1 parent 81e72be
commit 4d637ed
Showing 1 changed file with 29 additions and 21 deletions.
diff --git a/lib/aws.js b/lib/aws.js
@@ -39,10 +39,19 @@ exports.createMetaDataClient = metadata.init();
 
 // a generic AWS API Client which handles the general parts
 function genericAWSClient(obj) {
-  if (obj.secure == null) obj.secure = true;
+  var token = obj.token;
+  var signHeader = obj.signHeader;
+  var host = obj.host;
+  var accessKeyId = obj.accessKeyId;
+  var path = obj.path;
+  var agent = obj.agent;
+  var secretAccessKey = obj.secretAccessKey;
+  var secure = obj.secure == null ? true : false;
+  var connection = secure ? https : http;
 
-  obj.connection = obj.secure ? https : http;
-  obj.call = function (action, query, callback) {
+  return {call: call};
+
+  function call(action, query, callback) {
     // Wrap the callback to prevent it from being called multiple times.
     callback = (function(next) {
       var isCalled = false;
@@ -53,42 +62,42 @@ function genericAWSClient(obj) {
       }
     })(callback)
     // Try to set credentials with metadata API if no credentials provided
-    metadata.readCredentials(obj, function(err, obj) {
+    metadata.readCredentials(obj, function(err) {
       if (err) throw err;
       var now = new Date();
-      if (!obj.signHeader) {
+      if (!signHeader) {
         // Add the standard parameters required by all AWS APIs
-        if (obj.token !== undefined) query["SecurityToken"] = obj.token;
+        if (token !== undefined) query["SecurityToken"] = token;
         query["Timestamp"] = now.toISOString();
-        query["AWSAccessKeyId"] = obj.accessKeyId;
-        query["Signature"] = obj.sign(query);
+        query["AWSAccessKeyId"] = accessKeyId;
+        query["Signature"] = sign(query);
       }
 
       var body = qs.stringify(query);
       var headers = {
-        "Host": obj.host,
+        "Host": host,
         "Content-Type": "application/x-www-form-urlencoded; charset=utf-8",
         "Content-Length": body.length
       };
 
-      if (obj.signHeader) {
+      if (signHeader) {
         headers["Date"] = now.toUTCString();
-        if (obj.token !== undefined) headers["x-amz-security-token"] = obj.token;
+        if (token !== undefined) headers["x-amz-security-token"] = token;
         headers["x-amzn-authorization"] =
         "AWS3-HTTPS " +
-        "AWSAccessKeyId=" + obj.accessKeyId + ", " +
+        "AWSAccessKeyId=" + accessKeyId + ", " +
         "Algorithm=HmacSHA256, " +
-        "Signature=" + utils.hmacSha256(obj.secretAccessKey, now.toUTCString());
+        "Signature=" + utils.hmacSha256(secretAccessKey, now.toUTCString());
       }
 
       var options = {
-        host: obj.host,
-        path: obj.path,
-        agent: obj.agent,
+        host: host,
+        path: path,
+        agent: agent,
         method: 'POST',
         headers: headers
       };
-      var req = obj.connection.request(options, function (res) {
+      var req = connection.request(options, function (res) {
         var data = '';
         //the listener that handles the response chunks
         res.addListener('data', function (chunk) {
@@ -122,7 +131,7 @@ function genericAWSClient(obj) {
   /*
    Calculate HMAC signature of the query
    */
-  obj.sign = function (query) {
+  function sign(query) {
     var keys = []
     var sorted = {}
 
@@ -135,7 +144,7 @@ function genericAWSClient(obj) {
       var key = keys[n]
       sorted[key] = query[key]
     }
-    var stringToSign = ["POST", obj.host, obj.path, qs.stringify(sorted)].join("\n");
+    var stringToSign = ["POST", host, path, qs.stringify(sorted)].join("\n");
 
     // Amazon signature algorithm seems to require this
     stringToSign = stringToSign.replace(/!/g,"%21");
@@ -144,7 +153,6 @@ function genericAWSClient(obj) {
     stringToSign = stringToSign.replace(/\(/g,"%28");
     stringToSign = stringToSign.replace(/\)/g,"%29");
 
-    return utils.hmacSha256(obj.secretAccessKey, stringToSign);
+    return utils.hmacSha256(secretAccessKey, stringToSign);
   }
-  return obj;
 }